Observed Statewide Traffic Volume Patternstraffic volumes will continue to be monitored through-out the phasing period. The information provided in this weekly report is based on traffic

Observed Statewide Traffic Volume Patterns: Related to COVID-19 Monitoring

May 29, 2020

Oregon Department of Transportation 355 Capital St NE Salem, OR 97301 888-275-6368 For questions contact Becky Knudson: [email protected]

mailto:[email protected]

Oregon Department of Transportation May 29, 2020

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Introduction The purpose of reporting traffic volumes on the major state highways was initially designed to estimate the extent of compliance with stay-at-home directives aimed at eliminating non-essential travel and slowing the transfer of COVID-19. As of May 22nd, all but 3 counties will be approved for Phase 1 reopening1. Changes in traffic volumes will continue to be monitored through-out the phasing period. The information provided in this weekly report is based on traffic volume data collected by the Oregon Department of Transportation (ODOT) from Automatic Traffic Recorder (ATR) stations along the following state highway corridors: I-5, I-84, I-205, I-405, US-97, US-197, US-20, US-26, US-30, US-395, OR-18, OR-22 and US-101. Data are used from 38 locations across the state highway system, a list of which is provided in Table A and Figure A in the Appendix.

Year-Over-Year Change in State Highway Traffic Volumes Year-over-year comparison is an effective way of evaluating current traffic volumes relative to the same period in the previous year. This approach removes the effect of seasonal patterns and reveals trends, while avoiding misinterpretation of short term volatility as a longer term trend. The year-over-year change compares current traffic data to the same day of the previous year.

Figure 1 presents statewide weekday and weekend averages by week, illustrating the lower volumes associated with COVID-19 social distancing, beginning with school closures implemented the week of March 16, 2020. Weekday traffic volumes are slowly rising to levels seen last year, while weekend volumes are rising at a slower rate. The remainder of the report provides the detailed information behind these summary graphs.

Figure 1. Statewide Weekly Average Traffic Volumes

1 Source: https://govstatus.egov.com/reopening-oregon#countyStatuses accessed May 21, 2020

https://govstatus.egov.com/reopening-oregon#countyStatuses


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Table 1 provide traffic volumes for weekdays and weekends beginning March 16th. Corridor volumes are prepared by summing traffic volumes for ATRs across 13 corridors for years 2019 and 2020. This is a simple way to understand whether current traffic patterns are typical or measurably different. Changes in 2020 traffic volumes began in earnest mid-March, when schools were closed by executive order along with restrictions for groups over 25 people and restaurants being limited to take-out and delivery only. The most recent full week saw an average reduction of 21 percent in weekday traffic volumes and a 37 percent reduction in weekend volumes overall compared to the previous year. For the month of April, traffic began with 43 percent lower weekday volumes than 2019. By the end of April/ early May the difference declines to 29 percent below 2019 weekday volumes and 51 percent below 2019 weekend volumes. The most recent week marks a point in time when 34 of 36 counties are in Phase 1 of statewide reopening2, in addition to the Memorial Day holiday weekend. These two events coupled with nice weather are likely reasons for weekend volumes changing from 45 percent below 2019 volumes to 37 percent below. Continued monitoring will reveal actual trends.

Table 1. Observed Year-Over-Year Difference in Traffic Volumes by Corridor

2 Washington County has applied to begin Phase 1 on June 1st. Multnomah County has not applied for Phase 1 as of yet. County status is available online here: https://govstatus.egov.com/reopening-oregon

https://govstatus.egov.com/reopening-oregon


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Table 1 Cont’d. Observed Year-Over-Year Difference in Traffic Volumes by Corridor


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Observed Change in Total Traffic Volumes March 16 - May 27, 2020 Observing traffic volumes since mid-March reveals day-to-day travel patterns during the COVID-19 response period. Figure 2 illustrates day-to-day change in traffic volumes on 13 major corridors by indexing all days to volumes on Monday, March 16th. This enables direct comparison of patterns side-by-side across the entire state. Generally speaking, there was a downward trend the first week across all corridors, ending with a rise in traffic volumes on Friday March 20th for US-97, US-197, US-26, US-30 and US-20. Weekend traffic volumes dropped by 20 to 40 percent with the exception of US-26 and OR-18. The March 23rd executive order initiated further decreases in traffic volumes that week, where volumes declined 25 to 30 percent, with the exception of US-97 and US-197. Larger reduction in travel occurs on weekends, where trips are dominated by non-essential household travel.

Week one of the Stay Home order compared to the previous week reveals further decreases in traffic volumes. The largest decreases occurred on OR-18, US-26, US-20, US-30 and US-101, which see high use for commute and recreation-based travel. Week two after the Stay Home order reveals further decreases in traffic volumes in I-5, I-205, I-405, and I-84. US-97 and US-197 saw small increases in traffic volume relative to the previous week, likely related to rising truck freight movement. Volumes have been slowly increasing week to week.

Figure 3 and Figure 4 separate the corridors into two groups to better reveal detailed patterns. Figure 3 illustrates day-to-day change for I-5, I-205, I-405, I-84, US-97 and US-197. All of these highway volumes remained lower than mid-March, with the exception of US-97 and US-197. Initially, US-97 volumes began to increase on Friday April 3rd, with the following week higher on Wednesday, Thursday and Friday. Since the week beginning Monday April 13th, weekday volumes have been higher than those of mid-March, but remain about 19 percent below 2019 levels. US-197 volumes for Friday April 17th were nearly 20 percent higher than mid-March, the following Friday had similarly higher volumes as well. However, total volumes for this location are relatively low, March 16th volume was 2,400 and April 17th was 2,842. Seasonal patterns for US-197 begin to trend upward in April, so it will be important to be aware of seasonal increase versus change due to COVID-19 reduced travel, which is accounted for in Table 1 using year-over-year comparisons.

Figure 4 illustrates day-to-day change for US-26, US-30, US-395, OR-18, OR-22 and US-101. These highways have consistently been below March 16th levels, with the exception of the March 20th and 21st. US-395 volumes were about 4 percent higher than March 16th on May 1st, which was a Friday and payday for many people. Friday May 8th saw levels above March 16th for US-26, US-30, US-395 and OR-22. Overall, most highways follow a pattern of the highest volumes occurring on Fridays and the lowest on Sundays. Memorial Day occurred Monday May 24th, which impacted traffic volumes over the weekend on some corridors. Traffic monitoring will continue into the future as restrictions are phased out over time.


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Figure 2. Daily Change in Corridor Traffic Volumes Indexed to Monday March 16, 2020

Figure 2 cont’d. Daily Change in Indexed Corridor Traffic Volumes: May 1-27, 2020


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Figure 3. Daily Change in Traffic Volumes Indexed to Monday March 16, 2020: Interstate, US-97 and US-197

Figure 4. Daily Change in Traffic Volumes Indexed to Monday March 16, 2020: Non-Interstate Corridors


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Observed Heavy Truck Patterns Regional and national COVID-19 restrictions and global impacts to trade between nations influence the flow of freight in Oregon. Seventy percent of Oregon freight moves by truck, so looking at truck patterns by size reveals the net impact of these contrasting market forces. Freight originating from other countries, such as China, declined as quarantines were put into place and factories closed. Some domestic freight declined as Oregon businesses stopped or reduced activity. However, some domestic freight increased, providing goods needed to support essential activity, such as medical supplies, groceries and e-commerce.

Ideally, robust freight analysis would evaluate the flow of goods by commodity type, for example paper towels vs. car stereos. However, this level of detail is unavailable. For the last several reports information on total tonnage passing weigh-in-motion scales was used to monitor truck freight, but the information did not reveal any discernable patterns to support the analytical process. For this reason, the tonnage data is not monitored for this specific report.

In order to monitor truck freight movement, traffic volume data are used from 28 ATR locations capable of classifying vehicles by length. Table B in the Appendix provides the list of ATRs used to evaluate heavy truck volumes relative to light and medium sized vehicles. Light vehicles are defined as less than 20 feet long, typically composed of passenger vehicles, pick-ups, SUVs, and mini-vans. Medium vehicles are defined as 20 to 35 feet long, typically a mix of large passenger vans, cargo vans, large pickups, RV’s, utility trucks, single-unit 2-axle trucks, and other medium commercial trucks. Heavy vehicles are defined as over 35 feet long and typically include trucks with 3-axles or more.

Figure 5 illustrates how the proportion of vehicles by size has changed since the beginning of March. Before COVID-19 social distancing actions were implemented, heavy trucks made up about 12 percent of overall traffic. As COVID mandates were put into place, light vehicle traffic declined and the share of heavy traffic increased, as illustrated in Figure 5. Now that light vehicle volumes are rising, the proportion of trucks is moving toward typical levels.

Figure 6 illustrates heavy truck volumes since early March, with an added trend-line showing the overall trend based on the weekly volumes. Heavy truck volumes during the most recent week of May 14-20 are 12 percent lower than they were the first week of March. The lowest volume week for heavy trucks was March 25-31, which was 15 percent lower than the first week of March. During the last three weeks heavy truck volumes have remained steady and the overall trend is steady as well.

Figure 7 illustrates medium vehicle volumes, including a trend-line showing the overall trend since the first week of March. Volumes this week and last are the highest since early March. The lowest volumes occurred the week of March 25-31, which was 36 percent below the first week in March. Medium vehicle volumes are slowly rising and are expected to continue this pattern as restrictions are phased out before settling into steady-state levels.

Figure 8 illustrates light vehicle volumes, including a downward sloping trend-line. Volumes this week are about the same as last week, which are 32 percent lower than volumes during the first week of March. Current volumes are very close to volumes seen the week schools were closed. The lowest volumes occurred the week of March 25-31, similar to the pattern seen with medium and heavy vehicles. These volumes are expected to


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increase as restrictions are phased out. Time will tell if the increase in light vehicle volumes was due to the holiday weekend with nice weather or in response to all but two counties being in Phase 1 of reopening.

Figure 5. Share of Total Traffic Volumes by Vehicle Size

Figure 6. Heavy Vehicle Traffic Volumes


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Figure 7. Medium Truck Traffic Volumes

Figure 8. Light Vehicle Traffic Volumes


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Observed Change in Travel Time Reliability Note to readers: ODOT is currently shifting from one data platform to another. These tables will not be updated and expanded until we have full access to creating speed summaries reported in this section of the report

As traffic volumes decline, congestion declines, reliability and travels speeds increase. Table 2 reports the weekday afternoon peak period travel speeds for each week in March and April for corridors in the Portland Metropolitan region. Since mid-March most speeds are close to or at posted speeds for these six corridors.

Table 2. Average Weekday Afternoon Peak Travel Speeds

Table 3 reports the percent change in travel speeds relative to the previous week. The second week of March saw some impact to travel speeds, but the third week when the Stay Home order was initiated, average afternoon peak period speeds increased 14 to 68 percent across these 6 corridors. Since then, speeds have remained stable at free-flow speeds.

Table 3. Percent Change in Travel Speeds from Previous Week

Table 4 presents percent change in average weekday speeds indexed to the first week in March, illustrating how speeds have changed over time relative to the first week in March. Similar to the patterns seen in Table 4, speeds increased the most mid-March after social distancing policies were put into place, with the largest changes occurring on I-5, I-205, I-405, and OR-217. Continued monitoring reveals speeds are steady at free-flow levels across these corridors in the Portland region.

NB SB NB SB NB SB EB WB EB WB NB SBMarch 1-7 33 38 36 43 35 29 45 51 41 50 42 38March 8-14 35 42 40 53 34 32 46 49 43 54 48 38March 15-21 46 60 61 62 55 53 56 62 61 62 60 60March 22-28 60 60 62 62 51 56 60 61 61 62 61 61March 29-April 4 60 61 63 63 49 57 61 62 60 63 61 61April 5-11 60 61 62 62 50 57 61 63 61 62 61 62April 12-18 58 61 61 62 56 57 61 62 61 62 56 61April 19-25 60 61 62 62 56 54 59 62 60 62 60 60

WeekI-5 I-205 I-405 I-84 US-26 OR217

NB SB NB SB NB SB EB WB EB WB NB SB

March 8-14 6% 11% 10% 21% -2% 9% 2% -4% 6% 9% 14% 0%March 15-21 30% 42% 52% 18% 62% 68% 23% 25% 41% 14% 27% 61%March 22-28 31% 0% 2% -1% -8% 6% 6% 0% 0% 0% 1% 2%March 29-April 4 0% 2% 2% 1% -3% 0% 2% 2% -1% 1% 0% 0%April 5-11 0% 0% -1% -1% 1% 1% 0% 0% 1% -1% 0% 0%April 12-18 -3% 0% -2% 0% 13% 0% 0% 0% 0% 0% -8% -1%April 19-25 3% 0% 1% -1% 0% -5% -4% 0% -2% -1% 8% -1%

Week I-5 I-205 I-405 I-84 US-26 OR217


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Table 4. Overall Percent Change in Average Weekday Speeds since Early March 2020

As traffic volumes decline, congestion is reduced and travel speeds rise to posted speeds. Figure 9 illustrates how afternoon peak period travel times have changed across corridors in the Portland region since March 16th. The week before the March 23rd Stay Home mandate congestion began to decline. By the week of March 23rd, travel speeds are reliable and congestion levels low to moderate on most corridors, with the exception of I-5 that had a small spike on March 17th. Portland interstate highway speeds are now reliable and steady at or very near to posted speeds. Incidents where speeds dropped are associated with lane closures, which reduces capacity and creates a temporary bottleneck.

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NB SB NB SB NB SB EB WB EB WB NB SBMarch 1-7 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%March 8-14 6% 11% 10% 21% -2% 9% 2% -4% 6% 9% 14% 0%March 15-21 38% 57% 68% 44% 59% 83% 26% 21% 50% 23% 45% 60%March 22-28 81% 58% 71% 42% 46% 93% 33% 20% 49% 24% 46% 63%March 29-April 4 80% 60% 74% 44% 42% 94% 37% 22% 48% 25% 47% 63%April 5-11 81% 60% 72% 43% 44% 96% 37% 22% 50% 24% 46% 63%April 12-18 75% 60% 68% 43% 63% 96% 37% 22% 50% 25% 35% 61%April 19-25 80% 60% 70% 42% 75% 80% 31% 22% 48% 24% 45% 60%

WeekI-5 I-205 I-405 I-84 US-26 OR217


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Figure 9. Afternoon Peak Period Travel Times Indexed to Monday March 23, 2020


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Appendix

Table A. Automatic Traffic Recorder Locations

ATR Number

ATR Name Route ODOT Highway Number

Mile Point

County

03-016 Stafford I-205 064 0.76 Washington 26-024 Glenn Jackson Bridge I-205 064 25.50 Multnomah 26-027 Fremont Bridge I-405 061 3.05 Multnomah 03-011 Wilsonville I-5 001 281.20 Clackamas 10-005 Roseburg I-5 001 130.15 Douglas 15-019 Medford Viaduct I-5 001 28.33 Jackson 20-020 Martin Creek I-5 001 170.25 Lane 20-025 Eugene-Glenwood I-5 001 190.92 Lane 22-005 North Albany I-5 001 234.8 Linn 26-004 Interstate Bridge I-5 001 307.97 Multnomah 26-016 Iowa Street I-5 001 298.24 Multnomah 23-014 Snake River I-84 006 376.98 Malheur 26-014 Hoyt I-84 002 3.35 Multnomah 26-028 Fairview I-84 002 11.45 Multnomah 30-004 Pendleton I-84 006 203.34 Umatilla 33-001 Rowena I-84 002 75.93 Wasco 13-003 Hines US20 007 126.60 Harney 21-006 Burnt Woods US20 033 34.24 Lincoln 22-013 Waterloo US20 016 19.05 Linn 09-003 Lava Butte US97 004 142.41 Deschutes 09-007 Bend-Empire US97 004 135.95 Deschutes 09-020 Redmond US97 004 124.39 Deschutes 16-002 Madras US97 004 97.11 Jefferson 18-006 Chemult US97 004 204.65 Klamath 18-019 Midland US97 004 289.44 Klamath 33-005 Dufur US197 004 10.30 Wasco 16-006 Warm Springs US26 053 113.17 Jefferson 26-003 Gresham US26 026 14.36 Multnomah 34-005 Timber Junction US26 047 37.60 Washington 05-006 Rainier US30 092 53.33 Columbia 30-008 South Pendleton US395 028 1.77 Umatilla 27-001 Valley Junction OR18 039 23.23 Polk


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24-004 North Santiam OR22 162 2.82 Marion 04-001 Gearhart US101 009 15.90 Clatsop 06-009 Coos Bay US101 009 244.02 Coos 08-009 Port Orford US101 009 301.45 Curry 21-008 D River Wayside US101 009 114.91 Lincoln 21-009 North Newport US101 009 139.11 Lincoln

Table B.

0-20 feet (light)

20-35 feet (medium)

35-61 feet (heavy)

61+ feet (heavy)

03-011 09-003 15-019 20-020 23-014 30-00403-016 09-007 16-002 20-025 24-004 33-00104-001 09-020 16-006 21-006 26-004 33-00505-006 10-005 18-018* 22-005** 26-014 34-005*06-009 13-003 18-019 22-013 27-001 34-010*08-009

Length Classifying Automatic Traffic Recorder Location ID Numbers

* not included in 38 statewide traffic volume monitoring locations** As of 4/30/2020 length classification is no longer available due to hardware issue.

Length Bins


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Figure A. Location Map for Automatic Traffic Recorders

Documents

Observed Statewide Traffic Volume Patternstraffic volumes will continue to be monitored through-out the phasing period. The information provided in this weekly report is based on traffic